Battery electrode plate

Abstract

A battery electrode plate, characterized in that the battery electrode plate comprises an electrode plate body (1) and a tab (2); wherein the electrode plate body (1) comprises a current collector (11) and a coating (12) applied to the surface of the current collector (11), the surface of the electrode plate body (1) comprising a slit region (3) and a thinning region (4); wherein the current collector (11) is exposed on the surface of the slit region (3) of the electrode plate body (1) and is welded to one end of the tab (2); wherein the coating (12) is exposed on the surface of the thinning region (4) of the electrode plate body (1) and is located near the tab (2).

Description

TECHNICAL FIELDThe present invention belongs to the technical field of batteries, and specifically relates to a battery electrode plate.PRIOR ARTIf, in the current mobile telephone consumer market, they wish to occupy a certain market share and have sufficient product weatherability, the main direction lies in the areas of fast charging, high energy density, high safety performance and high and long cycle.As for the structure, the structure with centrally located tab predominates. In the existing center-located structure, in the existing technology, the slit for welding the tab is mainly preset before the cutting, and then, in the winding process after the cutting, the edge material facing the slit for welding the tab is punched by punching, however, addition of a punching work station device increases equipment cost, increases band breakage frequency during the process, and decreases winding efficiency, simultaneously, a series of problems have occurred, for example, electrode earth generated by the punching, which falls within the battery cell and affects K value and other performances; another method is to cut the slit portion in the cutting so that a part of the slit at an opposing position remains reserved for the electrode plate and the tab that are adjacent to each other. However, the slit in the non-welding region needs to be machined for cutting to prevent the aluminum foil in the slit of this region from being directly opposed to the cathode, and direct contact between the anode and the aluminum foil occurs when piercing the separator, which presents a risk of short circuit.CONTENT OF THE PRESENT INVENTIONAn object of the present invention is to provide a battery electrode plate in view of the deficiencies of the prior art, wherein by optimizing the electrode plate structure, the production process can be simplified, battery safety problems can be avoided and the quality of the battery can be improved.In order to achieve the above objects, the present invention uses the following technical solutions:a battery electrode plate comprising an electrode plate body and a tab; wherein the electrode plate body comprises a current collector and a coating applied to the surface of the current collector, wherein the surface of the electrode plate body comprises a slit portion and a thinning portion; wherein the current collector is exposed at the surface of the slit portion of the electrode plate body and welded to the end of the tab; wherein the coating is exposed at the surface of the thinning portion of the electrode plate body and is located near the tab.It is preferably provided that the thinning region of the electrode plate body is located between the edge of the slot region and the edge of the electrode plate body.It is preferably provided that in the width direction Y of the electrode plate body, the distance W between the edge of the slit region and the edge of the electrode plate body is smaller than the width L of the thinning region, where 0<W≤8 mm.It is preferably provided that the coating is formed in the thinning region with a thinning section, wherein the tab is located in the vicinity of the thinning section and the thickness h of the thinning section is 10-50 μm.It is preferably provided that the thickness H of the coating in the thinning region before thinning is 20-100 μm.It is preferably provided that the dilution thickness h1of the coating in the thinning region is 10-80 μm.It is preferably provided that the coating is of single-layer or multilayer construction.It is preferably provided that the coating comprises at least one of active material layer, safety coating, carbon coating and insulating coating in its thickness direction.Preferably, it is provided that the coating located in the slit region is formed with a slit, the slit comprising a bottom and a side wall, the side wall extending upward from the bottom, the bottom being a current collector exposed to the surface of the electrode plate body, the coating forming a side wall.A second object of the present invention is to provide a method for manufacturing a battery electrode plate, comprising:applying a slurry of a coating layer to a current collector; scraping or cleaning the coating of a slit portion by laser to form a slit;thinning the coating in a thinning region into a thinning portion;cleaning, roller pressing and cutting the electrode plate in succession;welding an end of the tab to the slit so that a part of the tab is close to the thinning portion.The advantageous effect of the present invention is that, in the present invention, the coating is thinned at a position of the thinning portion of the electrode plate body, that is, by thinning the coating at the position where the tab faces, the need to punch slits or cut slit portions after the slits is eliminated, which not only simplifies the production process but also avoids battery safety problems caused by the above process, thereby improving the manufacturing efficiency and yield of batteries. Moreover, a slit portion is provided on the surface of the electrode plate body, and the end of the tab can be welded to the current collector exposed on the surface of the slit portion, and the tab is located near the top of the coating in the thinning portion to avoid deterioration of the overall thickness of the battery cell. In the present invention, by optimizing the electrode plate structure, the production process can be simplified, battery safety problems can be avoided, and the quality of the battery can be improved.BRIEF DESCRIPTION OF THE DRAWINGSFeatures, advantages, and technical effects of exemplary embodiments of the present invention will be described below with reference to the accompanying drawings. FIG. 1 is a first schematic structural diagram of the electrode plate body of the present invention. FIG. 2 is a first schematic illustration of the electrode plate body of the present invention before thinning. FIG. 3 is a second schematic structural diagram of the electrode plate body of the present invention. FIG. 4 is a second schematic illustration of the electrode plate body of the present invention before thinning. Fig. 5 is a schematic illustration of a wide electrode plate of the present invention. FIG. 6 is a schematic illustration of a wide electrode plate of the present invention after cutting. FIG. 7 is a schematic illustration of laser cleaning of an electrode plate according to the present invention. Figure 8 is a schematic illustration of the operation of the laser emitter of the present invention. Fig. 9 is a schematic illustration of a scraping treatment according to the present invention.The reference numerals are explained as follows:1 Electrode plate body; 11 current collector; 12 coating; 2 tab; 3 slit portion; 4 thinning portion; 5 thinning portion; 6 slit; 7 laser emitter; 8 galvanometer; 9 field lens; 10 stage; 101 scraper; 102 fan; 103 vacuum-negative dust removing device; 104 support; Y width direction.DETAILED DESCRIPTIONThroughout the specification and claims, certain terms are used to refer to particular components. Those skilled in the art will appreciate that hardware manufacturers may use different terms for the same component. In this specification and claims, differences in names are not used as means for distinguishing components, but differences in functions of the components as a criterion for distinguishing. As mentioned throughout the specification and claims, "comprising" is an open term and should be interpreted as "comprising, but not limited to." "About" means that those skilled in the art can solve technical problems within a certain range of errors within this range, which can achieve technical effects in principle.In addition, the terms "first", "second", and the like are used for descriptive purposes only and cannot be understood to indicate or imply relative meaning.It should be noted in the present invention that unless otherwise specified and limited, the terms "installation", "connection", "attachment", or the like are to be broadly understood, for example, it may be a fixed connection or a detachable connection or integral connection; it may be a mechanical or electrical connection; it may be a direct connection or an indirect connection via an interposed medium; and it may be an internal communication of two elements. Those skilled in the art can understand the specific meanings of the above terms in the present invention according to specific situations.The present invention will be explained in more detail below in connection with FIGS. 1-9, but this does not represent a limitation of the present invention.First EmbodimentA battery electrode plate includes an electrode plate body 1 and a tab 2; the electrode plate body 1 includes a current collector 11 and a coating 12 applied to the surface of the current collector 11, the surface of the electrode plate body 1 includes a slit portion 3 and a thinning portion 4; the current collector 11 is exposed at the surface of the slit portion 3 of the electrode plate body 1 and welded to the end of the tab 2; the coating 12 is exposed at the surface of the thinning portion 4 of the electrode plate body 1 and is located near the tab 2.The existing structure requires the addition of a punching work station apparatus, which increases equipment cost and increases the band breakage frequency during the process and decreases the winding efficiency, and at the same time, a number of problems have occurred, for example, the electrode earth produced by punching, which falls within the battery cell and affects the K value and other performances; the slits in the non-welding region must be machined for the cutting. When piercing the separator, the anode and the aluminum foil come into direct contact, which leads to a risk of short circuit, therefore, by thinning the coating 12 at the position of the thinning portion 4 of the electrode plate body 1, that is, by thinning the coating 12 at the position where the tab 2 faces, there is no need to punch out slits or cut slit portions after slitting, which not only simplifies the production process but also avoids battery safety problems caused by the above process, thereby improving the efficiency and yield of battery production. Moreover, a slit portion 3 is provided on the surface of the electrode plate body 1, and the end of the tab 2 can be welded to the current collector 11 exposed on the surface of the slit portion 3, and the tab 2 is located near the top of the coating 12 of the thinning portion 4 to avoid deterioration of the overall thickness of the battery cell.In the battery electrode plate according to the present invention, the thinning portion 4 of the electrode plate body 1 is located between the edge of the slit portion 3 and the edge of the electrode plate body 1. Specifically, the slit portion 3 has a square shape, and the slit portion 3 is located near a side edge of the width direction Y of the electrode plate body 1, the area between the slit portion 3 and the edge of the electrode plate body 1 being the thinning portion 4. This can be understood to mean the slit edge material in the projection direction of the tab 2, i.e. the coating 12 which is located in the thinning region 4. Note that the protrusion direction of the tab coincides with the width direction Y of the electrode plate body 1.In the battery electrode plate according to the present invention, in the width direction Y of the electrode plate body 1, the distance W between the edge of the slit portion 3 and the edge of the electrode plate body 1 is smaller than the width L of the thinned portion 4, where 0<W≤8 mm. Specifically, the width L of the thinning portion 4 may be understood to mean the thinning length of the slit edge material in the protruding direction of the tab 2, the distance W between the edge of the slit portion 3 and the edge of the electrode plate body 1 may be understood to be the edge material width facing the tab 2, where W≤L, thereby ensuring that the coating material residues at the edge of the die cut slit need not be punched by the thinned coating 12 after the slitting, which does not affect the total thickness of the battery cell, thereby improving efficiency, yield, and quality of the battery manufacturing process.In the battery electrode plate according to the present invention, the coating 12 located in the thinning region 4 forms a thinning portion 5, the tab 2 is located in the vicinity of the thinning portion 5, the thickness h of the thinning portion 5 is 10-50 μm, and under the control of the thickness h of the thinning portion 5, the thickness of the slit edge material after thinning in the protruding direction of the tab 2 can be understood, for example, the thickness after thinning is 10 μm, 20 μm, 30 μm, 40 μm, 50 μm or the like, which may correspond to the tab 2, in order to avoid deterioration of the total thickness of the battery cell.In the battery electrode plate according to the present invention, the thickness H of the coating 12 in the thinning region 4 before thinning is 20-100 μm, which can be understood as the thickness of the slit edge material before thinning that controls the protruding direction of the tab 2. For example, the thickness before thinning is 20 μm, 30 μm, 40 μm, 50 μm, 60 μm, 70 μm, 80 μm, 90 μm, 100 μm, or the like, and the thickness may be the same as or different from the thickness of the coating 2 in other regions, which is not a limitation here.In the battery electrode plate according to the present invention, the thinning thickness h1 of the coating 12 in the thinning region 4 is 10-80 μm, which can be understood that the thinning thickness of the slit edge material in the protruding direction of the tab 2 is controlled. For example, the thinning thickness is 10 μm, 20 μm, 30 μm, 40 μm, 50 μm, 60 μm, 70 μm, 80 μm or the like, and the thinning thickness may correspond to the thickness of the tab 2 in order to avoid impairing the overall thickness of the battery cell.The lithium ion battery includes a battery cell, wherein the battery cell may include at least two stacked electrode plates having opposite polarities, the electrode plates having opposite polarities being a positive electrode plate of the battery and a negative electrode plate of the battery, respectively. In order to prevent a short circuit between the positive and negative electrode plates, a separator is disposed between each two adjacent electrode plates, and the electrode plates having opposite polarities are electrically insulated by the separator. At least one of the electrode plates may be the above-mentioned battery electrode plate.The at least two electrode plates may include a first electrode plate and a second electrode plate, polarities of the first electrode plate and the second electrode plate being opposite to each other, and the first electrode plate and the second electrode plate are stacked on each other.Specifically, the first electrode plate may be a positive electrode plate using the positive electrode plate structure of the above-mentioned Embodiments 1-8, and the second electrode plate may be a negative electrode plate; alternatively, the first electrode plate may be a negative electrode plate, and the second electrode plate may be a positive electrode plate, but this is not a limitation.In some examples, the battery cell may be a wound battery cell. The number of each of the first electrode plate and the second electrode plate is one, and the first electrode plate, the separator, and the second electrode plate are sequentially stacked and wound around the winding center to form a winding structure.In other examples, the battery cell may be a laminated battery cell. Here, there are a plurality of first electrode plates and a plurality of second electrode plates, the plurality of first and a plurality of second electrode plates are alternately stacked in the same direction, and a separator is disposed between each adjacent first and second electrode plates to electrically isolate the first electrode plate and the second electrode plate from each other.The functional principle of the present invention is:By thinning the coating 12 at the position of the thinning portion 4 of the electrode plate body 1, that is, by thinning the coating 12 at the position where the tab 2 faces, there is no need to punch slits or cut slit portions after the slits, which not only simplifies the production process but also avoids battery safety problems caused by the above process, thereby improving the manufacturing efficiency and yield of batteries. Moreover, a slit portion 3 is provided on the surface of the electrode plate body 1, and the end of the tab 2 can be welded to the current collector 11 exposed on the surface of the slit portion 3, and the tab 2 is located near the top of the coating 12 in the thinning portion 4 to avoid deterioration of the overall thickness of the battery cell.Second EmbodimentUnlike the first embodiment, the coating 12 of this embodiment is a single-layer structure or a multi-layer structure, the coating 12 including at least one of an active material layer, a safety coating, a carbon coating, and an insulating coating in a thickness direction thereof. Specifically, the thickness of the coating 12 may comprise one layer thickness or consist of two or more layer thicknesses. Here, one coating is an active material coating; two coatings may be a combination of an active material coating and a high-conductivity carbon coating or a combination of an active material coating and a safety coating, the safety coating being thermally stable and also containing coatings such as lithium iron phosphate having stable chemical properties; it may also be an active material coating and an insulating coating having pores, for example a ceramic coating; when three or more coatings are present, these may be a combination of any of the above-mentioned coatings.The other structures are the same as those in the first embodiment and will not be described in detail here.Third EmbodimentUnlike the first embodiment, the coating 12 located in the slit portion 3 is formed with a slit 6 in this embodiment, the slit 6 including a bottom and a side wall, the side wall extending upward from the bottom, the bottom being a current collector 11 exposed to the surface of the electrode plate body 1, the coating 12 enclosing a side wall. The slit 6 has four side walls, the four side walls and the bottom forming the slit 6, the bottom constituting the current collector 11 exposed to the outside, and there the tab 2 is welded to the current collector 11.The other structures are the same as those in the first embodiment and will not be described in detail here.Method for Manufacturing a Battery Electrode PlateA method for manufacturing a battery electrode plate, comprising:applying a slurry of a coating layer 12 to a current collector 11;scraping or cleaning the coating 12 of a slit area 3 by means of laser to form a slit 6;thinning of the coating 12 in a thinning region 4 to a thinning section 5;cleaning, roll pressing and cutting the electrode plate one by one so that the wide electrode plate is cut into a plurality of electrode plate bodies 1;welding an end of the tab 2 to the slit 6 so that a part of the tab 2 is close to the thinning portion 5.Note that the active material slurry is applied to both sides of the current collector 11 by a coating machine and rolled up after baking and drying;As shown in FIG. 5, the wide electrode plate is cleaned with a laser to form a slit 6, or the slit 6 is scraped with a scraper, or other methods are used to form a slit 6 for welding the tab 2;When forming the slit 6, by focusing the energy generated by the laser, the coating material on the current collector 11 can be cleaned. After cleaning the slit 6, the coating 12 at the edge of the slit 6 is again cleaned or the surface coating 12 is diluted by a scraper, and during the laser cleaning or scraper treatment, a vacuum-vacuum dust removing device 103 is added to remove the resultant electrode plate electrode ground, the laser power for cleaning the coating 12 at the edge of the slit 6 is again lower than the laser power for cleaning the slit 6;wherein, as shown in FIGS. 7 and 8, the laser cleaning apparatus includes, but is not limited to, a laser emitter 7, a galvanometer 8, a field lens 9, and a stage 10 which are arranged one after another from top to bottom. In the laser emitter 7, a total reflection mirror and an output reflection mirror are arranged in parallel, and the laser beam successively passes through the total reflection mirror and the output reflection mirror and then passes through the isolator to be emitted. The isolator plays a protection function by isolating the reflected laser in the process of work to ensure the safety of the optical path, the galvanometer 8 can reflect the laser light and refract it to various angles, the field lens 9 can control the focal length of the laser and can control the marking area, the stage 10 is at a lowermost position and can transport the electrode plate to a preset position for laser cleaning.As shown in FIG. 9, the scraper treatment includes a scraper 101, a fan 102, a vacuum-vacuum dust removing device 103, and a support 104, but is not limited thereto, the scraper 101 and the support 104 may be made of stainless steel or other metals, the electrode plate is fixed to the support 104, and the scraper 101 is perpendicular to the electrode plate. The coating 12 is scraped by a reciprocating motion, and on both sides of the scraper 101 are the fan 102 and the vacuum-negative-pressure dust removing device 103 capable of removing the produced electrode plate electrode earth.As shown in FIGS. 1 to 4, the coating 12 to be thinned may be a coating on the welding surface of the tab 2 or a double-sided coating. Depending on the actual situation, the slit 6 and the thinned coating 12 are obtained by laser cleaning or scraping and have to be cleaned physically again with a brush in order to remove the loose dust on the surface again. After passing through the dust-free paper wiping station, the surface dust is wiped to prevent the coating 12 from falling off in the thinning region in the subsequent processing, the thinning length L of the slit edge material of each tab 2 in the protrusion direction is: W ≤ L, the thickness H of the slit edge material before thinning in the protrusion direction of each tab 2 is set to 20-00 μm, and the thinning thickness hl of the slit edge material in the protrusion direction of each tab 2 is set to 10-80 μm, the thickness h of the slit edge material of each tab 2 in the protrusion direction after thinning is controlled to 10-50 μm; the coating 12 on the contact surface of the tab 2 may be thinned, or the coating 12 on both sides may be thinned;As shown in FIGS. 5 and 6, the electrode plate is subjected to a radiation pressing and cutting process, and the cutting process cuts the wide electrode plate into small electrode plates.In accordance with the disclosure and teaching of the above description, those skilled in the art of the present invention can also change and modify the above embodiment. Therefore, the present invention is not limited to the above-mentioned specific embodiments, and all apparent improvements, substitutions or modifications made by those skilled in the art based on the present invention fall within the scope of the present invention. Moreover, although some specific terms are used in this specification, they are only for convenience of description and do not constitute a limitation of the present invention.

Claims

A battery electrode plate, characterized in that the battery electrode plate comprises an electrode plate body (1) and a tab (2); the electrode plate body (1) comprises a current collector (11) and a coating (12) applied to the surface of the current collector (11), the surface of the electrode plate body (1) comprises a slit portion (3) and a thinning portion (4); the current collector (11) is exposed at the surface of the slit portion (3) of the electrode plate body (1) and welded to one end of the tab (2); the coating (12) is exposed at the surface of the thinning portion (4) of the electrode plate body (1) and is located near the tab (2).The battery electrode plate according to claim 1, characterized in that the thinning portion (4) of the electrode plate body (1) is located between the edge of the slit portion (3) and the edge of the electrode plate body (1).The battery electrode plate according to claim 1, characterized in that in the width direction (Y) of the electrode plate body (1), the distance W between the edge of the slit portion (3) and the edge of the electrode plate body (1) is smaller than the width L of the thinning portion (4), where 0<W≤8 mm.Battery electrode plate according to Claim 1, characterized in that the coating (12) located in the thinning region (4) forms a thinning section (5), the tab (2) being located in the vicinity of the thinning section (5), the thickness h of the thinning section (5) being 10-50 μm.Battery electrode plate according to Claim 4, characterized in that the thickness H of the coating (12) in the thinning region (4) before thinning is 20-100 μm.Battery electrode plate according to Claim 4, characterized in that the thinning thickness h1 of the coating (12) in the thinning region (4) is 10-80 μm.Battery electrode plate according to Claim 1, characterized in that the coating (12) is of single-layer or multilayer construction.The battery electrode plate according to claim 7, characterized in that the coating (12) comprises at least one of active material layer, safety coating, carbon coating and insulating coating in its thickness direction.The battery electrode plate according to claim 1, characterized in that the coating (12) located in the slit region (3) is formed with a slit (6), the slit (6) comprising a bottom and a side wall, the side wall extending upward from the bottom, the bottom being a current collector (11) exposed to the surface of the electrode plate body (1), the coating (12) enclosing a side wall.

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